No need to purchase basic membership. IMHO, PP only makes sense if you're going to make use of the "unlimited" option.
Plenty of lounges offer paid-for entry.
For ABZ, you can buy directly from
Servisair, but be warned that their lounges are a joke- I often prefer the public waiting areas, even when I'm entitled to access the lounge for "free".
However, for some reason, buying access to the ABZ Servisair lounge is cheaper when done through
Loungepass, where BKK's Louis Tavern Lounge is also available, as well as the Menzies AMS lounges. If you're silver, it may make sense to catch a few extra segments on UX or something and get yourself to Gold, at which point you'll also have guest access at no extra cost....For me, the Crowd Lounges at AMS are the best part of travelling with KL...