Present perfect continuous or past perfect continuous in my example

"I had been keeping an eye on this record for quite some time, ever since it went on sale. Each time I checked, I had been hoping for a price drop, but it seemed luck wasn't on my side until today and I finally bought the record"

Would like to know if past perfect fits well here? I think so because at the time of writing I don't keep an eye any longer and I am not hoping for a price drop any longer ,so present perfect continuous seems not right here : both situations keeping and hoping are not ongoing, they are over.

Regarding main question about the present versus past continuous, definitely not present. Past is correct for the reasons you wrote I think.

The first "Had been keeping and eye out" is a good choice, because "keeping an eye out" has a meaningful duration to it in your example. On this basis a continuous tense is totally appropriate.

The second "had been hoping for a price drop" however is a little strange (but not clearly wrong) because the sentence first introduces checking on the record, and checking a price is a momentary action with no meaningful duration or substructure. Using past perfect continuous in a clause which is already constrained to refer to a series of momentary events where the continuity of the verb outside of those events is irrelevant -- why bother using such a big tense when simple past is all you need?

This is making the point with a sledgehammer, but for example "I might have had already been finishing arriving home at five o'clock tomorrow" isn't technically wrong, it just sounds insane.

You could say "I hoped for a price drop" or "I hoped the price had dropped" instead, which avoids making any statement about the duration or the continuity of the hoping.