Not if you buy a decent lens. There's a good chance (if you buy wisely) that you'll recover most if not all of the cost by selling it on your return.

Just to take you down a slightly different route, I bought a bridge camera for a 'trip of a lifetime' to New Zealand. Fortunately I have no mobility issues, but nonetheless didn't want to cart all my kit with me and was prepared for the trade-off against my Pentax DSLR.

The camera did everything I wanted, including video, and I don't regret a penny of the expediture At the time Pentax didn't do an equivalent, but they do now!

On the other hand (from NT Visitor FAQ section)...

Q. Where can I take photographs?

A. Outdoors

All visitors to National Trust properties are allowed to take photographs out of doors for their own private use. Any individuals wishing to sell or publish photographs should contact [email protected]">[email protected].

Indoors

Amateur photography (including filming) without flash is now permitted in historic interiors at the Property Manager’s discretion. As with outdoor photography, any photographs taken are strictly for private use, and enquiries about selling or publishing photographs should be directed to [email protected]">[email protected]. However, visitors must be aware that at some places, there may be copyright issues, and further permissions may be required in respect of collections not owned by us. In these situations the Property Manager decision as to if photography is allowed is final.

Have a litle look (and play) here; link

The k-x is listed

Not sure reversed lenses will give you the lens-to-subject distance you seem to be looking for?

Maybe someone more expert than I can comment.

I have the 100mm Pentax macro - lovely lens - but it does only really only give 4-6 inches working distance.

Got one of these too. Trying it out with 2 x AF 160's. Nice and light!

On my HP it's Fn + F4.

Symbol on the F4 key looks like a place setting - knife and fork either side of a place mat!

Check out this site link for all things Pentax

I've got a 28-80 that I bought with my MZ-7. Nice little light-weight lens.

Is this the first time you've used your new camera?

Tried cleaning the contacts on the lens and camera body?

Be good if you could take and upload some images.

You might also want to look at the Pentax Remote F. Little infra red jobby.

If you have a K20D, then it'll operate the camera from both in front and behind. There are also 3rd party devices that do the same job.

Deciding factor is whether you mind being tethered to the camera or not. The one you're looking at has a 1 metre lead (I think).

Is this lens/tc combo new (to you)? In other words, have you used it before without problems?