Which CPU? Is the the M2 Pro w/ extra memory, or a base M2 Max?
Looking at the UK Apple refurb site, a 16" M2 Max 32GB/1TB runs £2,979.00. If that's what you're getting, you're getting quite a savings.
They have no refurb M2 Pro w/ 32GB in stock, but M2 Pro 16GB/1TB runs £2,369.00. If that's what you're getting with a bit more RAM, you're essentially getting an extra 16GB for just £31 over Apple's refurb price, but without the same guarantees a refurb from Apple would have.
It's most likely an M2 Pro. Whether the bonus RAM is a fair trade for a 2nd hand system is up to you. While the store may offer you warranty, you likely won't be eligible for Apple Care if that's something you'd normally consider.
In terms of will it last 3-4 years. Absolutely. Likely double that.
edit: Looking at new M3 Pro prices, going from 18GB to 36GB is £400. I imagine the M2 16GB to 32GB was similarly priced, then lowered a bit for refurb discount... let's say it's £300-£350 less than refurb from Apple. Not a bad deal, if it's truly in close to perfect condition.