Veracity of albums for sale being "sealed"?

Just wanted your opinions on whether or not the high prices of collectable albums should be so much higher for sealed versus unsealed albums. Could some of these be recently sealed after having been used, by a person with access to a wrapping machine? And how would the prosepctive buyer know? Thanks.
Post removed 
most all lps were sealed using shrinkwrap. Shrinkwrap, surprise, shrinks over time and the results were often warped records. Leaving the shrink wrap on an opened record was generally considered a bad practice. I'd be suspicious of any record that has been sealed in shrinkwrap for many years. The clear benefit of course is that the cover is protected and may be in good shape as a result.
"how would the prosepctive buyer know?"

Most "audiophile" pressings issued during the past couple of decades come sealed in loose bags of fairly thick plastic. And of these most have perforations along one side for opening. While it is possible to open and reseal these bags it is very difficult to do without leaving some indication of the reseal.

Most non-audiophile collectable albums come sealed in "shrinkwrap." The soft thin material is wrapped around the cover, the open edges are sealed with a hot wire and the package is run into a moderate-temperature oven for a few seconds, shrinking the material around the cover.

The latter process can be duplicated at home, but only with the proper material and a machine. It can be done, but takes some effort and investment or access to the hardware.

Over time the shrinkwrap tends to change shape, elasticity, and color. Duplicating a 20+ year old wrap is almost impossible with a new wrap. Additionally, the material used from the '60's through the late '70's was different from later material.

Close inspection of a previously-unwrapped and resealed cover itself will usually reveal some evidence that it was opened. Unless the original owner has been extremely careful there will be some less than perfect edges or scuffing or something similar.

So ... it is possible to "reseal" a package. But someone with moderate experience and a detailed inspection can almost always detect a prior opening.

As to value - the only way to ensure "new" vinyl status (distinct from a "perfect pressing") is for the package to have never been opened. Sometimes even one careful play will generate some noise or visible evidence (or cover wear as pointed out above). For many hardcore collectors anything less than "new" is unacceptable. It can also be very rare, which means the value can be quite substantial to someone who wants one.
Don't know about the authenticity of the seal, but I purchase lps to listen to, not look at.
I.m with Siddh on this. I don,t care how rare or sealed or not. I buy em to play and listen to them, period. Mapman's point is right on with "shrink wrap" and its effect over time and the risk of warped lp's. As Elizabeth pointed out , I myself have bought hundreds of lp's unsealed that don,t appear to of ever been played. The collectable status thing is in my opinion out of control, but as long as there are those that will and can afford to pay the prices for 12 x 12 wall art we music buyers will indefinately pay increases for good used copies. Cheers