Seedboutique is cheaper for there nirvana seeds. (think they cut a deal with seedboutique to stock there stuff so they can sell more).
But if buying more pricy strains I'd go with Doc over seedboutique...all three ship to US.
Both Seedboutique and Doc give free seeds
Nirvana I recommend for 1st timers due to there price. Be heart wrenching to ruin a pack of ten of DJ Shorts, Dutch Passions, etc stuff. Lose a chunk of money.