We're fortunate in this industry to have so many very affordable choices for POS software. In other industries, similar software can be 10-15k. In our industry it's from free to $1,500, due to healthy competition.
ALL of the top 5 products have excellent customer service, from what people always say. The forum has collected statistics for 6 years, to see what our members use. The results are at
http://www.custompictureframing.com/poll_results.htm#tech
Here's a neutral comparison list, to get started, which includes contact info for each company.
http://www.getthepictureframing.com/gfaq/software.htm These products all contain industry average markups, as a starting point.
Please note that pricing is a very personal thing that will vary depending on your buying power, profit goals, expenses, and local market. This is not a "set it and forget it" type thing to be taken lightly, and requires careful review. The settings that come with pre-made products are meant just as a starting point, to be tweaked/adjusted by the framer.
The professional point of sale and pricing systems will help keep you organized with records of everything framed, a mailing list that builds automatically, automatic due date scheduling, legible paperwork that doesn't show "part #s", consistent pricing with fewer errors, "pick lists" of what materials need to be ordered to fill your orders, twice weekly automatic price updates, and I could go on. It's a lot quicker than doing it on paper, especially when your customer wants to compare several options. It takes about 2 seconds to swap out a mat or moulding, to calculate the new estimate.
I suggest narrowing it down to a few, grabbing the free demos, and giving them a leisurely "test drive". Most products offer a 30 day demo, with no obligation.
Best regards
Mike