Well, nothing is really "cheap" in Amigaland... that said, for the best enjoyment experience and ease of use, just spring for some essential hardware.... if too expensive, you'll have too look around eBay. But, IMHO, after reading years of frustration in posts and going cheap ending up costing you just as much $$$ and a a LOT of wasted time, just go for these....
Accelerator........
http://amigakit.leamancomputing.com/catalog/product_info.php?products_id=1296But, IMO, just go for the good stuff here....
http://amigakit.leamancomputing.com/catalog/product_info.php?products_id=1285Scan Doubler.....
http://amigakit.leamancomputing.com/catalog/product_info.php?cPath=42&products_id=1148USB......
http://amigakit.leamancomputing.com/catalog/product_info.php?cPath=42&products_id=1213Internet.... for getting files the EASY way!
http://amigakit.leamancomputing.com/catalog/product_info.php?cPath=42&products_id=121or.....
http://amigakit.leamancomputing.com/catalog/product_info.php?cPath=42&products_id=116Really, that's all you need for hardware... trust me this is the easiest way to go.... although some will chime in with many other options. BTW, Indivision products just work.
Software..... gotta have.....
Internet....
http://www.ibrowse-dev.net/Word processor.....
Final Writer
Games....
WHDLoad
http://whdload.de/ game loader
http://www.whdownload.com/ where to get the games
http://www.lemonamiga.com/ check out thousands of games w/DL links
Unreal amount of software... use this, discover it, browse it, learn how to download from it.... it's awesome!
http://ftp://grandis.nu/user: ftp
pass: any
Aminet....
http://aminet.net/These will keep you busy for 6 months!

OK..... others will argue my advice till the cows fart the earth apart!!! :lol:
Oh, and install OS3.9 for the love of GEEEEEEEEBUZZZZ! Just get the real thing!!!! Me no likey the pre-packaged OS's.
Keeping it simple is what gives me the most enjoyment when installing hardware and software. And like nearly every Amiga head here... I've tried it all!!!
From there the sky's the limit for software.... audio, productivity, cheap external CD drive for USB, SH!T... too much to list..... :roflmao: