US Sales
Gran Turismo 3 - 7,140,000 (Heavily bundled, RRP $40, then $19.99 Greatest Hits)
Gran Turismo - 3,990,000
Gran Turismo 2 - 3,960,000
Gran Turismo 4 - 3,470,000
Gran Turismo 7 - ? (RRP $70)
Gran Turismo 5 - 3,440,000
Gran Turismo 5 Prologue - 1,340,000
Gran Turismo 6 - 1,240,000
Gran Turismo PSP - 1,050,000
If those numbers are anything like it won't be long until GT7 moves in behind GT3 for units sold. The respective RRP's are why it's already #1 for revenue.
GT Sport is unknown but didn't perform well on US Circana/NPD charts (revenue based). It was heavily discounted and bundled in Europe some 3-6 months after release.