If you're going to be connecting to the computer then you might not need a sampler built into the keyboard, because the keyboard could be used to play a sampler running on the computer, as well as other virtual instruments (i.e., computer programs that create the sounds of physical instruments).
On the other hand, if the person receiving the gift needs or wants to be able to use sampled sounds and expansion voices without having to be connected to a computer or laptop or tablet, then you'd probably want a built-in sampler or memory that can be used for adding new sound samples.
Be warned that many of the built-in samplers are rather basic in capability and functions-- as far as I know, they typically let you sample a sound, then they stretch or compress the sound waves in the sample to get different frequencies so the sample can be used across the width of the keyboard, which can be fun (like recording yourself saying "hello" and then playing it back as anything from a slow-talking basso profondo giant to a fast-talking chipmunk), but not very useful musically since sampling one note of a musical instrument and then applying it to 128 different MIDI note values doesn't yield very convincing results. It's much better to record a separate sample for each and every note, including sampling each note at multiple velocities, as well as being able to layer two or more samples together. To my knowledge, people who create their own sound samples generally use a computer to do all the hard work of recording and editing and layering the samples, then they create a soundfont or similar format that can be loaded into a keyboard as an expansion voice.
So (in my opinion) it's better to have a keyboard with memory and functions for loading new sound samples, as opposed to one that has built-in sampling functions. I'm sure there must be keyboards out there that do have built-in samplers plus sophisticated editing functions which rival the best sampling software for computers, but those keyboards are probably way out of your price range.