2x3" photos

Hi everyone, i need a new printing website to use. I used to use LaLaLab in the UK but they cant ship to the USA anymore if the price is less than $800. I LOVED their 2x3 photos and the pricing was great.

Anyone know of a website i can use to print 2x3" photos that is not expensive? (i have over 600 photos i need to print)

or if anyone knows a good app to make a collage so i can put 4 photos on a 4x6 photo. All the apps ive tried just do square photos.