If I remember correctly the first with my own money was actually three. Styx-Paradise Theater, Journey-Escape and REO Speedwagon-Hi Infidelity. The first bought for me when I got a new 8 track tape deck at Christmas 1979 for my Midland hi performance stereo receiver was Kiss-Alive II, Van Halen 1 and Joe Walsh-...But Seriously Folks.
I had to mow half the neighborhood for it. It later got warped all to hell in the back seat of the car. Vinyl...
Pink Floyd Dark Side of the Moon, and i have the 2 original tour posters that came with the albums framed and on my living room wall.
I got my first record player when I was 4 so my first albums were kid records that mom bought, Alvin & The Chipmunks among them. The first adult record that dad bought me at my request was The Spectacular Johnny Horton in 1960 (I was five). Horton sang my two favorite songs in 1960--"Sink the Bismarck" and Battle of New Orleans". The first album that I bought with my own money was either Whipped Cream (Tijuana Brass) or Meet The Beatles in early 1964. I forget. I still have these records and they are in great shape.
I don't remember the first album I ever bought but I remember the first one my younger brother bought. It was Iron Butterfly. I must heard Inna Gada da Vida 10,000 times in a month until his record "disappeared"