Replacing your toilet can be a good thing if you are really bored with the old fixtures that do not work as efficiently as they should. You may have some issues matching the other fixtures if they are a special color. For the most part you can replace all the faulty fixtures along with the design and look of your toilet. Also, if you have tile around the bottom of your toilet it is sometimes hard to find a matching toilet because of design changes and you may need to also hire a tile repair man to match the tile back.
When you are thinking to replacing your toilet you may want to consider repair instead. With what I mentioned above it can be costly for you. You can lower down your budget by considering repair rather than replacing it completely. There can be some minor problem with your toilet and fixtures that can be repaired easily and thus can save you money. There are Plumbing Parts supply stores that have repair parts even for very old and specialty toilets such as markspp.com .