Its tough to say.. I bought all my original Tull stuff in the mid 1980's so I cant say in todays pricings... But as far as tull goes... if they are all in good shape and are as follows:
Aqualung: Reprise label with lyrics sheet insert and cover is somewhat canvas-like then excellent deal. If its a green label Chrysalis, not as good. If its a blue/white Chrylasis it is a common post '76 pressing and less valuable. Also, listen to the end of Wind up (last track) there should be an extra (ghost track) verse "I dont believe you, you got the whole damned thing all wrong, im not the kind you have to wind up, on sunday" That was not included in the later pressings.
Thick as a Brick: Jacket should not be glossy, label should be brown Reprise with complete LARGE Newspaper fold out in gatefold. Green Chrysalis is later pressing, and Blue/white Chrysalis is not so special.
If they meet the above "original" criteria id say that you did good considering there was no shipping involved!
When Tull collecting for originals, keep in mind that the Reprise label ran through 1972, from 73 to 75 they ran a green chrysalis label, and 1976 and later had the blue/white chrysalis label.
For 'This Was' (68) and 'Stand Up' (69) you should keep your eyes peeled for Brown Reprise labels that have an orange top segment (two-tone). These are especially rare first pressings. (more-so for 'Stand Up'.... that in 2-tone is a true rarity)