Need a new rear wheel

bragawd

Hi all i need a new rear wheel... I'm told the one on my giant xtc 2 isn't suited to my weight 94kgs thats why its probably egg shaped atm..
so I'm looking to get a new hoop...
will it be cheaper to get one built using my HUB off the old wheel...
OR just buying a new one... ATM my no good rear is a mavic x117 disc
I havent got a BIG budet but will go to like £60_80 ish ... at a push .. not sure whats out there without looking into it proper