There's quite a range of prices you can pay for a sight pusher. A "professional" universal model sight pusher can easily cost several hundred dollars. My first sight pusher came from SIG, made specifically to fit SIGs and that was a little over $100. My second sight pusher came from www.sightpusher.com, a general purpose pusher that cost about $60. They have a nice demo video that shows how to use it on a 1911.
I've used the SIG sight pusher on a P220. Clamped the slide firmly in the pusher, cranked down on the adjustment screw, nothing happened. More cranks, nothing happened. More cranks, then heard a loud "POP". Thought to myself, d**n I cracked the slide! Checked the slide and all was well. The POP was just the rear sight breaking free. Gave me quite a scare though. In retrospect, buying two sight pushers is likely more expensive than having a smith do the job and hopefully he does not scratch up your sight. Yet, it's nice to have the tool since after moving the sight, more adjustments may have to be made to fine tune the setting. Your call. Hope this helps you make a choice as I am not a sight pusher expert. Having that gunsmith do it for $25 doesn't sound bad at all.
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