so the rega planar 3 is probably about astep up the rung in terms of table quality from the the debut esprit that you were looking at.
Im not sure how that cartridge stacks up overall but I’ve heard bad things about the carts on the lowest regas and good things as you go up through the range. I’ll let someone else jump in on that.
One thing to consider. The rega has a manual speed change. You have to take off the platter and move the band onto a different rung of the platter every time you want to change from 33 to 45 and back again. This is a major pain if you’re into 7” or if, like me, you have a fair sized collection of albums cut at 45. The project you were looking at does it at the push of a button (it’s what the sb in the name stands for.
Also consider in your new range a pioneer plx1000 for £550. it doesn’t come with a cartridge but you could look at pairing it with a Grado gold (roughy £250) if that doesn’t break the bank!
if they have them in stock at the price you want I’d highly recommend
www.analogueseduction.net as a dealer, I’ve bought nearly my entire system from them and they’ve always been fantastic with me.