Don't know if this qualifies in the bargain section or not but,
Stainless Automotive Fasteners stock every conceivable size of machined metric stainless steel screw you could want for a bicycle, excepting the really specialised shoulder-type bolts used as brake pivots, and at a very reasonable price.
Admittedly, their website could do with a bit of a sort as the titles down the left-hand side of the page are very hard to read as they run into one another, but as well as bog ordinary hex socket head cap screws (allen bolts to you) they do reduced-size ones which has the head from the bolt the size down on the next size up (M5 head on an M6 bolt) which are great for fitting into the pocketed holes one finds in handlebar-to-stem clamps etc. They also sell screws with half-height heads so they don't stick out as far, and most important for me washers which are the same diameter as the bolt heads, again essential for fitting into pocketed holes.
I realise they are not anodised (there are places that will do this for you) or polished (get the right abrasive products, job done) and they aren't as light as titanium, but once I'd added up the Ti weight-saving and realised it was in the order of 40 grammes (around the weight of a car key and fob, possibly less) and the horrendous cost of same I went down this route. Give 'em a try.
