Do you sell Basis A2, A7 and A9 envelopes in packages of 50? I really don't need 250 each.

We sell select colors of the Basis A2 and A7 in packages of 25.  Basis A-9 envelopes are only sold in boxes of 250 Envelopes.  You may also want to browse our Pop-Tone Envelopes as most of the colors are offered in 50 packs.

Will this fit inside another a7 as an inner envelope?

No, it will not fit into another A-7 envelope.  We do carry Cougar A7 inner outer envelopes as a set.

Are the olive envelopes the same olive as the LEBAFT-A7-OLIVE-50 flat card invitations?

Yes, they are both Basis Olive and will match each other.

Do these envelopes go through a lazer printer?

They are laser and inkjet compatibile as long as your printer can handle printing on this size of envelopes.

The card is 4.25 x 6.50" so I would have to go with a A7, right?

The A7 Envelopes measure 5.25 x 7.25 inch and The A6 Envelopes measure 4.75 x 6.5 inch.  They will fit in an A7 Envelopes but there will be quite a bit of extra space, and unfortunately, the 4.25x6.5 inch card will not fit into an A-6 Envelope.