A guitar signed by rock legends the Rolling Stones is one thing (sold in Canada earlier this week for $10k); but how about a guitar signed by Prince Harry of Wales?
The 25-year-old British Royal isn't known for his blistering guitar solos - but he still signed the £500 electric instrument owned by Paul Sundt after watching Sundt's band perform live three years ago.
Now Mr Sundt is desperate to find out how much his once mid-priced guitar is worth.
"The guitar does mean a lot to me but I've got a new one now so I wondered how much it might be worth," said Mr Sundt, according to the Royal news website M&C.
"I have great memories about the night we played when Prince Harry turned up. He was really pleasant and chatty and just like one of the lads.
"His bodyguard even got up on stage with us and sang Wild Thing."
The Prince was completing his army training in Dorset when he saw Mr Sundt's band, Beaver, play at gig at Lulworth Army Camp.
A rare autograph
Price Harry is normally reluctant to sign his name - which means Mr Sundt's treasured axe could be a valuable and appreciating collectible.
At the Beaver gig, Mr Sundt was thrilled to see the Royal dancing to his band's music. He spent time with the group after their show and even went away with a Beaver t-shirt.
In return, Harry gave out autographs, including signing Sundt's guitar "Harry Wales" with a smiley face.
"At the end I asked Harry if he would sign theand he said he would think about it if we kept on playing. It was a tongue in cheek bribe we were happy to accept," Mr Sundt told the Dorset Echo newspaper.
Mr Sundt has taken the instrument to Duke's auction house in Dorchester to find out its value. So a signed Prince Harry guitar could soon be coming to an auction block near you.