They should not fit too snugly, or they will be more susceptable to tearing. Varying degrees of padding are available in the back of the hand and fingers, which can be useful for epee and sabre fencers.
Gloves can deteriorate rapidly under heavy use, often lasting a single season or less.
Economical alternatives to genuine fencing gloves include precision welding gloves, motorcycle gloves, and even common workman's gloves available at any hardware store, provided the fingers and palm are unpadded and supple enough to maintain the feel of the blade. It may be prudent to hand-stitch a longer gauntlet onto the cuff, if the normal one doesn't cover the sleeve opening. In all these cases, a small wire opening may have to be cut into the wrist.