Each homeowner would get to pay $12 a month, in addition to pass-through costs associated with new fees imposed on businesses. For example, a restaurant could expect to pay $200+/month, while a brewpub might pay $600+/month - $7200/year.
The proposal puts business fees anywhere from $6 per month to $2,754 per month, depending on the choice of fee structure and scope of business. The former is a barber shop under the $8 per month charge, while the latter is a "mega-retailer," that generates more than 250,000 trips per month.
Actually, this being Porkland, it's a safe bet that the $8 per month fee supposedly under consideration isn't going to happen; the city's going to go with a minimum of $12 a month because it'd chafe them to leave that "extra" money on the table. And if you think a retailer's just going to swallow an additional $33,000+ per year in "street fees", I've got a light rail bridge to sell you.