I love this question, so forgive the long-winded response. I guess I'll preface this by saying that prices in the midwest are incredibly competitive and we have some seriously amazing shops in Cincinnati. So needless to say, if you're the store paying 10% of retail you won't be here for long.
I'll start by saying this is a bit of a loaded question. I can't necessarily give a broad answer to this, because it depends on the record. The reason I say that is because, if you walk into my store right now and try to sell me a copy of Stadium Arcadium by the Chili Peppers, you're going to be disappointed (
Red Hot Chili Peppers - Stadium Arcadium). Sure, the cheapest copies are $100 and it's only going up from there until they get time to repress it again. But, I have a warehouse with around 225 copies remaining (had 1,000 in January) and I put them out in the store each week, all the time, for $44.99. They actually used to be a bit cheaper too, but I had to get my last batch from a middleman/one-stop. So, they go for $100 on discogs in this little blip of time . But in the real world, once manufacturing catches up, it's a $40-50 record. And also, you can walk in my store tomorrow at 12 p.m. and buy a brand new sealed copy for $44.99(I think I actually have a used copy in the bins for $35 right now, too!). My whole philosophy as a store is, I don't want you to buy this record today, and when the repress shows up in a week, you walk in and find it brand new in my bins for half or less of what I charged you last week. It's a seriously fine line, especially in today's world. Mellon Collie is an absolutely classic example of this. Nine Inch Nails the Fragile is another one. In the last 6 months, there's been multiple times where folks walked in and wanted me to pay more for an opened used copy of those records than I had them for sale for on my floor. I keep a lot of stock out of inventory for locals. I had copies of Mellon Collie until late January this year actually, still for sale at normal retail. Someone walked in and wanted $125 for an opened copy, and I showed them my sealed copy for (at that time) $99.99 on the floor. They're not wrong, and I'm not wrong, it's a weird gray area right now, right? I try my best not to follow the market that's moving on the monthly up and down cycles.
All that being said, if there's a limited reissue that's legitimately out of print, and this stuff is way easier when the record has been gone for 5+ years, I'll absolutely pay 50%, 60%, and even up to 65% cash depending on the record. The other thing to consider is that everyone's idea of retail value is different, right? Some folks consider the discogs median, some folks consider the discogs average, and some folks go with the highest. I tend to price based on a sort of in-house combination of all of those 3 and also use gripsweat and popsike for more rare items. I think I could talk forever on this subject, and if anyone has made it this far I'm sorry for typing so much. I think the best thing to do is actually show you some examples.
Don Carol - You Want No One But Me - We sold for $2499.99 a few months ago - the seller was paid $1,667.00 for this and we took on the risk of selling an incredibly rare G condition 45 that was cracked. Something that, discogs won't give you any info on regarding price, popsike will only show you 1 hit, and that's all you have to go on. We made $833 on the sale, minus $92 in Paypal fees, ~$55 on overnight mailing and insurance, minus the normal overhead of paying the mortgage + 26 employees. What we brought to the table for the seller was the ability to grade properly, provide sound clips for the customer, and also find the right sales channel for this. Stuff like this doesn't sell to an average collector. Which also means that the grading has to be on point, especially when the condition is this bad. In VG+ condition, this is easily a $6,000+ record. We have a strong email list we've built over the years and also pay dearly for the monthly fees on (I think $500+ per month at this point). But, that email list is what allowed that record to find the right customer. It's also what allowed us to make such a generous (or as my Dad would tell me, foolish!) offer.
Another good example would be a local customer who brought me around 300 records on Tuesday. It was a mix of older rock stuff, newer rock/metal stuff, and some random country thrown in. I told him what I tell a lot of folks in that situation. If you give me 1-2 days to sort through, you'll always get paid more. Yesterday morning, one of my buyers and I spent the time sorting through, cleaning, and pricing all 300 records. We put them in our system and figured out the retail value for the entire batch. Retail in our store was $6,400, which was actually a really impressive number considering the quantity. I will say, there was definitely some out there metal stuff. This wasn't all Metallica and Megadeth that was going to fly off the shelves. I offered the customer $3,500, cited my retail price that we calculated, and they were more than happy.
If you go on our site, you'll find some high dollar 45s. Some are sold, some are still in stock. I can guarantee we paid at least 50% for all of those, and in some cases, much more. In some cases, I totally fucked up and paid wayyy too much.
Online Store <-- There's a link to expensive stuff on the site, either in stock or out of stock.
When it comes to lower dollar stuff, yes, we have to be more conservative. I pay 50% for most stuff below $30.
But, to answer your original question, if you bring me a $200 record that I agree with your retail on and we will price at $200, you'll likely get $100 or more. If you're a regular customer that shops with us it's very likely I'd offer something like $110 cash / $130 trade.
Sorry again for the novel.