I suppose to answer the question are RIBs too expensive ? - They are until you can afford to buy what you want !
If I had £150K + to spend on a boat would I buy a Rib for that much ?- no , but I am happy to spend what I have done so far on what I have. if I had £150k to spend on aRIB - I'd buy several boats to differant things with.
A 10k boat is very very expensive for some , but for others a £50k boat is not expnsive. I think its down to personal choice. You dont have to spend big big money on a boat when a used one will do the same , if not better . It may not be the right colour for you , but if its 25-50% less money can you live with it ? I know I can live with alot if its cheap enough !
Some of the known brands I think you are paying for the name when you can get somehting tthat is 90 % as good for 50% of the cash.
Or better for 50% of the cash !