Buy a used professional-grade tool on Ebay. Snap-On, Kent-Moore, K-D tools, etc. There are bunches of them there, and they never wear out. I've been using the same air-operated valve spring tool for over 30 years. There's one identical to mine listed under "used valve spring compressor" today for $30.00 along with a bunch of others.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!