theres ALOT you can do to the Sawtooth in terms of Processor acceleration
http://www.sonnettech.com sells G4 upgrades in 800mhz, 1000mhz, 1200mhz, and 1400mhz running you anywhere between $240US and $500US so you can really do something that fits your budget, lots of options
also the PC100 memory is cheap.
as little as $160 for a 1GB chip (pricewatch.com)
and $60 for a 512mb. The ram ceiling on the Sawtooth is 2GB, with 4 slots to work with, so very inexpensive options.
if you get the processor upgrades, you really arent going to be able to tell any difference unless you have at least 1GB of ram
macaddict just did a feature on upgrading G4's such as the sawtooth and mentioned that an upgraded 1.4ghz /1gb ram Sawtooth ran twice as fast as the stock 400mhz / 256mb
you certainly have alot of options mate.