My personal preference would be to keep it in house for the following reason: control. When you outsource these types of operations you lose direct control over what is happening with them and if your outsourcing partner does not do a good job you could be in serious trouble. The 2/3 people working for you there have already established themselves and you trust them to take care of your business. Besides, if you have any trouble with them it's much easier to find replacement help than it is to try find a different outsourcing partner or bring it all back in house. Not only that, but after you outsource you lose control of the cost structure as well. Your outsourcing partner may start you on a 1-2 year contract at a reasonable rate, but continually up it on you in subsequent years to the point that you may be forced to bring it back in house anyway.

Additionally, your expenditure can be capitalized over a period of time allowing you to offset the costs of the new equipment against your taxes, which should ease the burden some. Another thing an improved accounting package may do for you is allow you to reduce your Days Outstanding for Accounts Receivable and improve your payment speed on Accounts Payable to hit some of those NET10 or NET30 invoices (if you have any). At some point this investment will break even for you, so even though you have a large initial outlay it's not like you're losing the money.