Yes, you can. You can sell our designs fully unbranded or customized or in a package with your other services. There is an option in the affiliate area to disable the template prices and affiliate buy links and offer templates like this. Offering like this you let the clients view, choose, contact you about the chosen template, then buy the template needed for the project from us (through the affiliate link or shopping cart), customize and charge the custom project or the template based package price through your shopping cart. It should also be noted that selling like this you may NOT sell templates as STANDALONE products at a price different than the price on TemplateMonster.com and through your shopping cart.
If you have more questions feel free to contact our affiliate support by submitting a ticket request.