Do I REALLY need to buy the special "Longines Spring Bar Tool"?

I have been on the fence about buying the Legend Diver L3.764.4.50.9 (black rubber strap) for months now, but the price is an issue. I searched all of the available offers, did the math, and figured out that it would be cheaper to buy the Legend Diver L3.764.4.50.0 (brown leather strap) from a fairly reputable jewelry-store chain that cooperate with my card's cash-back program (which Longines does not), buy the black rubber strap from Longines, and sub out the straps. I bought the watch itself as planned and went to buy the replacement band from Longines directly, but Longines upped the price on the black rubber strap and tacked an optional Longines Spring Bar Tool on to my order, thus diminishing my cash-back savings. I am displeased and I don't want to pay the extra $20 + tax for the Longines Spring Bar Tool unless such tool is really necessary. Is it, or can I get one for less money from another seller? I looked at the tip of the Longines Spring Bar Tool and really it looks just like a seam ripper in a standard sewing kit - doesn't SEEM to be any magic to getting the Longines tool, but please let me know your thoughts / experiences. Thank you!