You can throw lots of trick factory parts and money to sportify the 228i, like the Sport Line ($2,300) or the M-Sport package ($3,000), dynamic handling ($1,400) and lighting packages ($900) outside, the brushed aluminum trim ($500) and power front seats with driver memory ($995) inside. Check the M-Sport box and those after it, though, and you're up to $39,820 and probably better off negotiating yourself into the M235i.
You'll find fewer options in that M-ified column and lower prices for some of the shared accessories; it takes $4,500 to add the premium package to the 228i, but $2,300 to install it on the M235i. Even so, you can find yourself north of $52,000 for an M235i before you've finished gorging yourself at the option buffet.
Head over to 2Series.org to give the ordering guide the proper forensic treatment. Note: if the text looks strange to you, it's because one of the fonts is missing all of its lowercase 'l's and 'i's.