So I went through tcgplayer and added them all up. I came up with exactly $500 for the whole set of all 35 promos that I have. I do have extras of some cards that I'll throw in for free. I didn't put them in the spreadsheet. I have, in addition to the set pictured, and will throw in for free all these:
2x more mew #8
1x more pikachu #60/64 1st ed WD gold stamp
1x more pikachu #26
1x more arcanine #6
1x more entei #34
1x more team rocket's meowth #18
3x more evee #11
4x more cool porygon in original packaging
3x more cleffa # 31
1x more smeargle #32
About $200 extra worth, I think, according to tcg player. I won't go through the effort of selling all the duplicates individually... just not worth my time.