Looking for a cheap bicycle

Haven’t shopped in a while.  Entry level road bikes at a shop will run $700 or more, but that should include a basic fitting and a tune up after you’ve ridden a month or two.  To that, you can add pedals, shoes, tire repair kit, spare tubes, pump, water bottle cages, seat bag, helmet...some of that, you can get at your favorite big box store.  

You can try bikesdirect.com and get something for $400, but it doesn’t include assembly, fit, or tune-up.  You might find something at a big box sporting goods store.  

A road bike is pretty efficient, so faster for the same effort, or alternatively less effort for the same speed.  This is because the 700x23 Tires are pumped to 100 psi.  You can get ”flat bar” road bikes or a fitness bike if you don’t like the hunched over riding position.  As the tires get wider, the pressure goes down, so 700x28 might be 70 psi and 700x32 50-60 psi.  The tires and wheels also get heavier.  Any of these would be doable for the 56 miles, but requires more energy and will be noticeably slower (Maybe 15 mph vs 17).  A fitness bike with 700x28 tires could be a good “all around “ bike if you’re only going to have 1 bike.  The tires are more durable and you sit up where you can see traffic.  

An additional point...

for a 70.3, don’t expect changing tents, so you’ll want a pair of tri-shorts and probably 2 pairs of bike shorts.  Be aware that some of the cheaper shorts are thin...I held up a pair from a big box store and could see right through them.