Some software are such that even though you don't use them based on cost constraints, they are good - or better, or even the best. And you desire to use it sometimes when you get a chance.
Followup Boss falls in this category. As a solo agent, one may want to still try and hire buyer's agent and see the results. With starting cost of only $149/month - and 20% discount (at the time of writing this review) I'd say, it is worth it. About $1,000 for the year means you can surely convert one lead by a perfect follow up. Not to mention about 90% of leads falls through the crack because of the lack of the follow up!