As the guys are indicating, relative to what you can get them done for by somebody who as got the gear - at £5 a corner I definately wouldn't bother myself. Times I've had mine done it was £16+VAT per corner or £10 beer tokens per corner by somebody doing them privately (done by a mainstream tyre company employer who was able to take the mobile van home for emergency call outs).
Since then I bought one of them DIY manual things and quite honestly it's a waste of money. I've since changed my own on the truck using 3x24" tyre levers and probably the only time I use my high lift farmers jack. I put a piece of shaped wood on the tyre so as not to damage it, use the tow bar of the truck as an anchor point and push the bead off using the jack.
From there scrap the crap from the inner wheel rims, coat the rims with the black tyre sealant. Give the tyre rim a coat of tyre soap stuff to soften the rubber and lever the replacement tyre back on using all 3 levers. I allways put a new valve in just for safety sake. When your putting the tyres back on you have to make sure the opposite tyre rim is right in the centre of the wheel to give you maximum levering on the rim your fitting. I remember an old post on here when somebody was having a pop at I believe Camskill because of a damaged tyre rim. Having done the DIY tyre change, I reckon Camskill were in the clear and it was the fitter that damaged the tyre because he didn't get the opposite rim bang centre of the wheel.
Going back to your scenerio, if alloy wheels are part of the equation, chances are you would be better advised to get some of the plastic rim protectors to save the soft alloy when being levered against. Plus the other downer is getting the wheels balanced after the refit.
Conclusion for my money, I wouldn't bother. Better trying to find somebody that will do the fitting and balancing for £10 or less per corner.