Hi cupcake,
i use vistaprint for most of the yamahaclub merchandise, im pretty sure Sachas shirt was a basic t-shirt but as seen in her pic it seems to accomodate her features well,
From looking at VistaPrint, it seems the only printable womens t-shirts they have are signiature soft ones (some brand name, idk) which start at £14 a pop, if you want XXL (and im not saying you do, i mean IF) its another £1, front and back printing is then £5 on top of that, so all in all £20 for a ladies shirt, as opposed to the basic mens t-shirts which start at about £5 each before printing.
If you would like a definate price send me a pm with your requirements (shirt type, size, colour, what printing you want and where) and i can send you a preview and quote