"Getting on the internet" used to be just about reading HTML pages.... which did not require much of anything in the way of resources. We browsers were very light, and did not have big memory signatures. Pages were written with text and a few graphics.
The wolrd has changed. No longer can you get that old beater PC "just for gettin on the net"
The problem is, the web browsers of today (Netscape 4/IE4 and up) all use tons of RAM. Just opening pages with less than 64 megs and you will be swapping to disk like crazy.... I dont like a "net" machine to have less than 128.
Also, it aint just HTML text anymore. Something like half of all major websites use Flash or similar animated technology in some way. This is very CPU intensive. Now we have javascript, real audio, tons of different multimedia applications,.... and all of these use RAM and CPU.
75mhz aint gonna cut it... unless you like to wait... and things not even work. Evergreen upgrades are not worth the money. Find a cheap used system, if you want to save money... that is at lease a PII-266, and takes DIMM memory, so you can upgrade it inexpensively. I have seen a system like this with a 10gb drive, CD, 266, and 256 ram sell complete for $150.
Much better choice.