Hardware Extreme has just taken a look at a round up of inexpensive HSF that give acceptable performance, However they are not really suitable for any overclocking. If you need budget cooling for a computer that will always stay at stock speeds then these are perfect. Here's a snip:
"CPU cooling is a very important part of the computer. An improperly cooled CPU will cause instability in the system and may end in the destruction of both the CPU and Motherboard. Today heat sinks range in cost from an $80.00 Swiftech to a $9.00 Evercool. Today we'll be taking a look at three very inexpensive Evercool heat sinks."