If you are too frugal to buy the best, then you are not really that serious about Good Photography.

The good news is that if Photography turns out to be a frustration, it's so easy to say... "Oh well, I should have purchased a better camera?"

The 20D was better than the 30D (but not a lot)
The 40D was much better than the 30D
The 50D was more megapixels than the 40D, but a wash for some people on IQ over the 40D
The 60D was a good bump up from the 50D, actually spectacular.
The 70D.....who knows...It's NEW!!!!

But take the price differential and divide it by the number of months you think before you'll be lured up.

The new Canon 60D body is $550 at Amazon
The new Canon 70D body is $1200 at Amazon

The difference is $$650. Say two years - That's $27.03 per month, or six 20oz Lattes at Starbucks. That's a quarter of a tank of gas in a guzzler, and 3/4 of a tank in anything getting over 25MPG hi-way. That's the difference to own the better camera. 90 Fracking cents a DAY!!!

Another thing, there is little or no DNA on the new 70D when you pull it out of the box. Heaven knows what hands have touched the 60D. In fact, if you get a used lens with the used 60D, how do you know the previous owner didn't spit on the lens and wipe it with a shirttail to get the smudges off?

Take that one step further. Do you know if that same guy did his own sensor cleaning.... UUUUUGH!!!

The 70D will undoubtedly be better, but no easier to use than the 60D... figure 3-6 month to get to know either one well.

Foolish to ask for a comparison on this forum (of all forums) as there is minimal anecdotal evidence on the 70D because it is so new. (I often wonder why people ask for comparisons on a generalist forum like UHH... If you are spending big bucks you should ask your question on a camera specific forum, of which there are many for Canon... certainly not here.)

Any way, the 70D makes more sense.

Also, you can use my "pseudo rental" program. Buy the latest and greatest, particularly if it's mid or pro level and turns out to be a hot item..

Shoot it for three months and make a serious evaluation. If you don't like it, place a good ad on eBay. Sell it. If you do a good job and commit to the three month rule, you should only be out $100 to $150 for the whole 3 month period. You can't touch that figure if you rent for that long. You'd be out more like $300 to $400 total if you rented a body alone for 3 months. Then you would still have to pony up new price for the camera. One would have to be suffering brain cell degradation to go that route.

I LMAO at those who suggest "rent and try". I have done this (buy it, use it and care for it 3 months, sell it) and always recovered within $150 on my price. And that's not use it and take it back and screw a merchant. That's buy and sell. Take the risk.

In variably I have fully justified the acquisition of the latest model at least 6 times now. In fact, I bought two new camera's, one a Nikon D90 when they first came out, and one a Canon, and shot both of them alongside each other for three months. Neither one cut the mustard and I resold both and my expense over 3 months on cost was about $260 total.

Used camera's can be great....

1) if budget dictates
2) your commitment to good photography is mediochre
3) You listen to people on these forums, because nobody else has the same criteria you do, and you don't know if they would actually spit on the front of a $1500 lens to clean it.
4) Some of your advisors (the people you ask) actually don't use their cameras. They sit on these forums and rehash the same old advice, because they really don't have a life that involves going out and getting the pictures.

Kinda like me. Only been shooting about 48 years now.