I'm amazed by this thread (actually I'm not). I've done a fare bit of DIY in the past including plastering which I regard as a black art even though I am reasonably good at it (still wouldn't touch a ceiling though!).
Yes, we are all chasing the cheapest price for whatever we buy, whether that be a pint of milk, a piece of steak or a room plastering - or even an extention. It's not as simple as a price per hour. You have to understand and accept the quality and compare with others offering the same skill. Then you make the call. It may be the cheapest but they may not be the most refined. Some tradesmen may be asking for £500 a day plus mats but their quality and inspiration are top notch. It's your choice.
As this is a photography forum this can also be associated at wedding photographers. Let's face it £250 a day for weddings seems reasonable to me.
(Quickly runs away to get flak jacket and tin hat). However, hopefully people get the point that you generally get what you pay for. Also, what someone thinks looks easy, when they try, they may realise there is a lot of skill involved, both mentally and physically.