clasher

I dunno if that'll play nicely with the front derailleur or not... shimano says 20T capacity for the FD. The FD also has a shaped cage for certain kinds of rings so that factors into things too. I don't know how much it really matters but it might.

Here's a shopping list that might work out for you to convert this to a 3x8 touring setup with lower gears
triple crank
113mm bb (might need longer/shorter spindle)
8 speed cassette 11-32
alivio rear derailleur
8 speed bar ends
8 speed chain
fd-2403 triple FD
tektro levers

Add another 10-20$ for new cables and housings, you'll likely more housing for the bar-end shifters for the front part of the cable runs but you might be able to reuse both the brakes housings and cables, but probably have to get a new cable for the rear derailleur (maybe even a tandem shifter length if you have a big frame and long stem) and use your current RD cable for the front derailleur. I don't know what the used parts market in your area is like but I doubt you'd be able to recoup the cost for all those new parts. If you can get a 150 for them all (which is optimistic in my mind) you can save half the cost of all those parts. When selling the parts call them "take offs" since they are used but haven't been riding. You might also wanna check out what your LBS would charge to do all this work and if they'd comp you for the take-off parts, heck they might have a bin with some or all of the parts you need from other people's bike that changed them out when they purchased their bikes new.

This isn't the only way to go about this kind of thing either, sometimes buying an entry level hybrid with a 3x9 drivetrain at a bike shop and having them put drop bars, levers and bar-end shifters might work out to be cheaper than the mail-order touring bike and drive-train swap.