A problem with items such as crank pullers is that if they have poorly-machined and ill-fitting threads they may well damage an expensive component while you are trying to use them. If the cheap puller strips out your crank threads then you will either have to obtain another tool to remove the now-damaged component or resort to destructive removal methods. In either case you will have a cheap, useless tool and a ruined component. I have found that cheap tools are rarely a bargain; you generally end up replacing them with the tool you should have bought in the first place, like zebede did.

An alternative would be to take your bike to a shop and have them remove the cranks for you; this might be the best if you only plan to do this job once.

Good tools are empowering; if you have the tool you may make use of it more than you think, taking care of small jobs like BB maintenance yourself proactively instead of ignoring them or having to have someone else do it for you.