Okay, let's see how this goes, haven't done a price suggestion in ages. (and yes, I own one, trying to increase value of my backpack, yada yada, accuse me of whatever you want)

SOLD

http://www.tf2outpost.com/trade/11932328 - 1st one, 3.5 Buds. Seems like an outlier

2nd Owner (so many trades...)

http://www.tf2outpost.com/trade/11934652

http://www.tf2outpost.com/trade/11954102

http://www.tf2outpost.com/trade/11963926

http://www.tf2outpost.com/trade/11958588

And he got offered up to 7 buds pure and the Roboactive Fez (~7+, that's the highest pure offer atm http://www.tf2outpost.com/trade/10958349) + Lantern Ballcap (4.6-5.1)

3rd Owner

http://www.tf2outpost.com/trade/11984441

http://www.tf2outpost.com/trade/12047537

He's had pretty much only crap offers though, best being Sulphorous Beak (15 bud b/o but no offers, same for phosphorous so hard to tell), 6 Buds, and the Timewarp Firewall + 100 Keys which is by far the best offer it seems but he instantly declined it, that offer being around 4 buds pure + the Firewall, I have crap internet so hard to check past trades and the such but it seems like they're asking for quite a bit, so probably around 10? Please correct me if I'm wrong.

EDIT: Saw some guy offer like 310$ on a past trade which is like 8 buds pure so yeah, okay, whatever.

2nd Unbox

No outpost trade but I have my trade history. I did Peace Snaggle + Bubbling Fez + 1 Key + Tuxxy or something, obvious outlier.

MEEEE

Now, for some reason, the offers I've been getting seem to be quite good. The other owner "Capitan Coraje" offered to buy mine for 10 pure. Feel free to ask him or I can screenshot that proof if neccessary.

http://www.tf2outpost.com/trade/12125602 That's my trade btw. "Mercato #Dream Hatter" also offered tentatively the Sunbeams Bonk Boy if I added ~2 buds or so, so that offer is once again 10-12 approximately.

And lastly. Anti-Freeze Full Metal Drill (~7) + Phosphorous Attendant (?) [idk about attendant, at least 5 though]

Overall Offers

3.5 Pure OUTLIER

7 Pure

Roboactive Fez + Lantern Ballcap [~12 Buds]

Sulphorous Beak [???]

6 Pure Lowball

Timewarp Firewall + 100-120 Keys [~14? Buds]

Peace Snaggle + Bubbling Fez [~really cheap] OUTLIER

Beams Bonk Boy -2 Buds [~12-14 Buds]

Anti-Freeze Full Metal Drill + Phosphorous Attendant [~12]

10 Pure

Also, note how short some of the trades have been up.

Conclusion

10, being the highest pure offer, should probably be considered the low value as it's the only pure offer that hasn't been like instantly rejected by anyone.

~13, high range as several offers that seem to be ~12 buds, some high, some lower, aaaand yeah believe it's been proved possible.

[I hope I did alright in this suggestion]