In the world of comic collecting, Superman reigns supreme. Action Comics #1 which introduces him is the most desired on the market and a copy may be worth up to $1m if in excellent condition.
Heritage is currently holding an auction in which the top lots are from the 1950s - the so-called Silver Age of Comics - all based around The Man of Steel himself.
An issue of Adventure Comics #247 (1958), rated 7.0 by the CGC, has already taken bids sufficient to sell for over $2,000. The cover shows 'Superboy' being rejected for membership by the 'Legion of Super-Heroes' (Cosmic Boy, Lightening Boy and Saturn Girl).
A first issue of unlikely spin-off Lois Lane #1, also graded as 7.0 and from the same year, shows Lane flying alongside her boyfriend thanks to a witch's broomstick. A collector will have to part with at least $1,200 to beat bids already made.
Supergirl was introduced in issue #252 (1959) of Action Comics, and a 7.0 grade copy is on offer here as well.
Fans less interested in Superman may be tempted by an issue #39 of Spiderman which is rated near-mint 9.2. It's a relatively common issue, but nevertheless an attractive one for a collection. The issue reveals the identity of Spiderman's foe the Green Goblin.
The prices mentioned are likely to rise as there are still two days of internet bidding possible before the live auction in Dallas on Sunday.
After that, comic book fans will be looking forward to Heritage's February auction, at which a high grade Detective Comics #27 (introducing Batman) is expected to draw six figure sums.