I really want this card, but have to fore-go others to do so

[Smarti5051]

I am guessing the more expensive card is one that does not come up as frequently as the cards you mentioned, either because it is in a higher grade or has better centering or is just rare. The three cards you referenced selling are awesome cards, but they are all fairly easily attainable down the line in similar condition. Plus, while you are in a position to liquidate a few cards now to get the "big one," you might not be in that same position in a few years. Whereas, you will likely find opportunities in the future to reacquire the cards you sold by squirreling away some funds and or selling lesser cards that have appreciated. Just my 2 cents.

[sb1]

As above, ask yourself if you could buy the same card tomorrow if you wanted it back(not identical card, just one like it, same graded, etc), if the answer is yes, sell and buy the big one. If it's something really rare/scarce that you own and probably could not replace it for some time if ever and probably even then, at a higher cost, you might want to stand pat.