It costs fewer Singapore miles to fly United economy flights to Europe than the same flight costs with United miles, and neither award has fuel surcharges.

Conclusion: book United economy awards to Europe with Singapore miles instead of United miles.

From Singapore's award chart:

27,500 miles one way in economy to Europe (United charges 30k)
65,000 miles one way in Business Class (United charges 57.5k)
80,000 miles one way in First Class (United charges the same)

Singapore does not collect fuel surcharges on awards of United flights, so those economy awards on United flights are just cheaper

When United greatly devalued its award chart in February 2014, it started charging more to fly Business and First Class on its partners than on its own planes.

Through April 20, 2015, United is offering up to a 30% discount on purchased miles. The size of the discount depends on the number of miles you buy, with the largest 30% discount kicking in at 30,000 miles purchased.

United miles normally cost 3.5 cents per mile plus a 7.5% tax, bringing the full price to 3.76 cents each.

Through April 20, 2015, United is offering up to a 30% discount on purchased miles. The size of the discount depends on the number of miles you buy, with the largest 30% discount kicking in at 30,000 miles purchased.

United miles normally cost 3.5 cents per mile plus a 7.5% tax, bringing the full price to 3.76 cents each.

This blog became famous because I was the first to articulate how to book free one ways on United and US Airways awards.

A free one way is a one way trip to or from your home airport that is tacked onto another award for no extra miles.

Wandering Aramean got "part of an internal memo describing [United's] plans for the coming year." It says:
Deliver first phase of united.com 2.0 by 2q 2015, including bundled ancillary offerings;
Some time in this quarter (by June 30), United plans to roll out a new website with new bundled fare options, which sounds like what American Airlines offers. Not that interesting. Moving on...
begin introducing dynamic award pricing.
Uh-oh!

"Dynamic award pricing" would mean that award prices change, presumably based on the cash price of the underlying ticket.

Wandering Aramean got "part of an internal memo describing [United's] plans for the coming year." It says:
Deliver first phase of united.com 2.0 by 2q 2015, including bundled ancillary offerings;
Some time in this quarter (by June 30), United plans to roll out a new website with new bundled fare options, which sounds like what American Airlines offers. Not that interesting. Moving on...
begin introducing dynamic award pricing.
Uh-oh!

"Dynamic award pricing" would mean that award prices change, presumably based on the cash price of the underlying ticket.

United is offering a 20% discount on roundtrip Saver economy awards booked to Hawaii by April 19 and flown Mondays through Thursdays from April 14 to May 19. The total cost of a roundtrip is 36,000 miles.

Don't Book This Promotion
If you have United miles, this may be a good deal. If you have Ultimate Rewards, do not transfer them to United miles to book this deal.

United is offering a 20% discount on roundtrip Saver economy awards booked to Hawaii by April 19 and flown Mondays through Thursdays from April 14 to May 19. The total cost of a roundtrip is 36,000 miles.

Don't Book This Promotion
If you have United miles, this may be a good deal. If you have Ultimate Rewards, do not transfer them to United miles to book this deal.

United is offering a targeted bonus on purchasing miles through March 23, 2015 that varies from 20 to 50%. Check your email for the subject line: "Reveal your bonus: Receive up to a 50% bonus when you buy or give miles"

When I clicked "Reveal my bonus >" in my email, I learned that my bonus is 25%.

United miles cost 3.76 cents each. With my 25% bonus, they cost 3.01 cents each. If you get a 50% bonus, your miles will cost about 2.5 cents each.
Is even 2.5 cents per United mile a good deal?
No.