To be honest, I think PKA are a little shady. Seem very well run and organised, but also seem like they are more interested in getting your money than teaching you to defend yourself. I dont like that you "have" to buy your own gloves, shin pads and foot guards in order to be able to grade - I dont like the fact that you "have" to grade, and I dont like the fact that when you do grade you get charged £26 for a belt. All that on top of the already expensive membership fees is ridiculous. Credit where its due tho, they do know their stuff, and are very friendly
You don't have to grade. No one will make you. Just out of interest, when did you last enquire? The membership has gone down recently. I see what you mean, though - still quite expensive.
Do you have a link to the PKA. I did a search but found nothing. The only PKA I know of was back in the 70's and 80's and they went down due to legal problems and such. I don't think that this is the same orginization.