For most "normal" modern computing tasks, (web browsing, music, email etc), the 500MHz era G3 iMacs are more than up to the job and will motor along nicely with Tiger and a decent amount of RAM. $70 (c. £35) is a pretty average price for one of these at the moment so if it's in good condition then it'll be a pretty good deal.
As far as I can remember, these iMacs use PC100 SDRAM and perhaps also PC133. Not all PC100/133 modules will work however, so it would be best to check for compatibility before buying. In the UK the normal price for a Mac-compatible PC100 DIMM is around the £20 mark but this will likely be different in the States.
As far as I can remember, these iMacs use PC100 SDRAM and perhaps also PC133. Not all PC100/133 modules will work however, so it would be best to check for compatibility before buying. In the UK the normal price for a Mac-compatible PC100 DIMM is around the £20 mark but this will likely be different in the States.