Photography is a very difficult thing to master, and although it may seem that now digital has come into play that it is less time consuming, but infact, a) It is more reliable, b) there is much more post processing that is done in house where as quite often it was done external whilst photographers were using negatives, c) the outlay for decent digital equipment is much more expensive and there is less of a second hand market, plus software, computer hardware and quite often either the outlay of learning to use software or paying someone who knows how to use it.
Also please remember that the photography industry really does not give you any assets, the only assets that you may have is your equipment or your copyright, where as equipment devalues copyright does too unless whomever has had their pictures taken becomes famous etc so the photographer could then re-sell for more money. Essentially your copyright is your pension.
Photography is a very difficult industry to crack, not only do you have to be self employed but you also have to keep up with changing times and the megapixel wars, as opposed to a trade such as building or plumbing were systems do not change. When you first try and get into the industry you have to work for very little money, and then when you are a photographer you have to constantly tout for work.
Also we cannot factor out insurance, I have public liability £1 mil, professional indemnity for £250000 and equipment cover to the tune of £7000 and this costs me £200 /year. Add this to the cost of time, equipment, transport, tax, NI, costs of post production and printing and employment of other professionals..... lawyers (for when clients dont pay, illegally reproduce images etc.....) and accountants etc we're talking a large outlay thus i think photographers are just in their charges and asset protection for themselves.
Ways that you could consider negotiating is to take a lease as opposed to paying for copyright, with a lease you would have the option to reproduce the print for a set amount of time.
FYI the average wedding photographers yearly wage is around £24,000, not much for what often adds up to 12 hour days.