Is it fairly common for student glider pilots to have wing tip strikes, especially in gusty cross wind conditions? Is it fairly common for student glider pilots to have wing tip strikes, especially in gusty cross wind conditions?
I understand gliders are landed level, slow down and then the wing drops onto a wing tip wheel or skid plate when coming to a stop.
Which begs the question, are gliders more prone to wing strikes by student pilots prior to or after landing due to the mono wheel arrangement and low wing tip clearance, or have poor cross wind landing ability in gusty conditions (say 10-15mph gusts above the headwind) when compared to a tail dragger or tricycle wheel arrangement?
Yet thousands of gliders around the world are used every week with the mono wheel arrangement, with a mid wing arrangement that is only 2-3' off the ground.
My gut feeling says no, as gliders have been around probably for 100+ years and they would have changed from mono wheel to a tail dragger, at least on the trainers by now if wing strikes were common among student glider pilots. This is probably due to the lateral stability of a long wingspan and the mid wing arrangement means the glider is landing in a nice stable pillow of air in ground effect.
Most gliders have dihedral, giving more wingtip clearance than you probably are envisioning.  Many glider pilots routinely use the wing-down (slipping) method of crosswind correction.
As far as general handling while landing in gusty crosswind conditions, most tailwheel airplanes sit in a much more nose-high attitude than most gliders, and have the landing gear much further forward ahead of the CG, and therefore are much more prone to ground-looping.  And groundloops often involve wingtip contact with the ground-- on the downwind side.
On the whole the crosswind limits below which a safe landing without damage to the aircraft can reasonably be expected, are likely higher for most gliders than for most tailwheel light airplanes.
As for the part of your question contained in the actual title-- no, it is not common for student glider pilots to strike the wingtip into the ground before the main wheel touches.